diff --git a/signalr/signalr.d.ts b/signalr/signalr.d.ts
index ab7c88186f..a32b5ee1ae 100644
--- a/signalr/signalr.d.ts
+++ b/signalr/signalr.d.ts
@@ -21,6 +21,11 @@ interface SignalREvents {
     onDisconnect: string;
 }
 
+interface SignalRStateChange {
+    oldState: number;
+    newState: number;
+}
+
 interface SignalR {
     events: SignalREvents;
     connectionState: any;
@@ -53,8 +58,8 @@ interface SignalR {
 
     starting(handler: () => void ): SignalR;
     received(handler: (data: any) => void ): SignalR;
-    error(handler: (error: any) => void ): SignalR;
-    stateChanged(handler: (change: any) => void ): SignalR;
+    error(handler: (error: string) => void ): SignalR;
+    stateChanged(handler: (change: SignalRStateChange) => void ): SignalR;
     disconnected(handler: () => void ): SignalR;
     connectionSlow(handler: () => void ): SignalR;
     sending(handler: () => void ): SignalR;